Problem: $\dfrac{4}{3} - \dfrac{2}{4} = {?}$
Solution: $ = {\dfrac{4 \times 4}{3 \times 4}} - {\dfrac{2 \times 3}{4 \times 3}} $ $ = {\dfrac{16}{12}} - {\dfrac{6}{12}} $ $ = \dfrac{{16} - {6}}{12} $ $ = \dfrac{10}{12}$